packfile: define and use bsearch_pack()
[git/git.git] / packfile.c
index f26395e..69d3afd 100644 (file)
@@ -1654,6 +1654,29 @@ out:
        return data;
 }
 
+int bsearch_pack(const struct object_id *oid, const struct packed_git *p, uint32_t *result)
+{
+       const unsigned char *index_fanout = p->index_data;
+       const unsigned char *index_lookup;
+       int index_lookup_width;
+
+       if (!index_fanout)
+               BUG("bsearch_pack called without a valid pack-index");
+
+       index_lookup = index_fanout + 4 * 256;
+       if (p->index_version == 1) {
+               index_lookup_width = 24;
+               index_lookup += 4;
+       } else {
+               index_lookup_width = 20;
+               index_fanout += 8;
+               index_lookup += 8;
+       }
+
+       return bsearch_hash(oid->hash, (const uint32_t*)index_fanout,
+                           index_lookup, index_lookup_width, result);
+}
+
 const unsigned char *nth_packed_object_sha1(struct packed_git *p,
                                            uint32_t n)
 {
@@ -1720,30 +1743,17 @@ off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
 off_t find_pack_entry_one(const unsigned char *sha1,
                                  struct packed_git *p)
 {
-       const uint32_t *level1_ofs = p->index_data;
        const unsigned char *index = p->index_data;
-       unsigned stride;
+       struct object_id oid;
        uint32_t result;
 
        if (!index) {
                if (open_pack_index(p))
                        return 0;
-               level1_ofs = p->index_data;
-               index = p->index_data;
-       }
-       if (p->index_version > 1) {
-               level1_ofs += 2;
-               index += 8;
-       }
-       index += 4 * 256;
-       if (p->index_version > 1) {
-               stride = 20;
-       } else {
-               stride = 24;
-               index += 4;
        }
 
-       if (bsearch_hash(sha1, level1_ofs, index, stride, &result))
+       hashcpy(oid.hash, sha1);
+       if (bsearch_pack(&oid, p, &result))
                return nth_packed_object_offset(p, result);
        return 0;
 }